some addresses resolve wrong on Lucid

Problem: address resolving
Well, I performed a fresh install of Lucid and everything worked well until I found myself unable to install addons on Firefox and XChat refused to connect to freenode (other networks seem to work well).

I ran some tests with two different machines: one with Lucid, the second with Intrepid. Both are on the same LAN:

With Lucid:
@wget https://addons.mozilla.org/en-US/firefox/downloads/latest/722/addon-722-latest.xpi?src=addondetail

--2010-05-11 12:15:27-- https://addons.mozilla.org/en-US/firefox/downloads/latest/722/addon-722-latest.xpi?src=addondetail

Resolving addons.mozilla.org... 63.245.213.91

Connecting to addons.mozilla.org|63.245.213.91|:443... connected.

HTTP request sent, awaiting response... 302 Found

Location: https://addons.mozilla.org/en-US/firefox/downloads/file/88048/xpi/noscript-1.9.9.74-fx+sm+fn.xpi?src=addondetail [following]

--2010-05-11 12:15:28-- https://addons.mozilla.org/en-US/firefox/downloads/file/88048/xpi/noscript-1.9.9.74-fx+sm+fn.xpi?src=addondetail

Reusing existing connection to addons.mozilla.org:443.

HTTP request sent, awaiting response... 302 Found

Location: http://releases.mozilla.org/pub/mozilla.org/addons/722/noscript-1.9.9.74-fx+sm+fn.xpi [following]

--2010-05-11 12:15:29-- http://releases.mozilla.org/pub/mozilla.org/addons/722/noscript-1.9.9.74-fx+sm+fn.xpi

Resolving releases.mozilla.org... 32.1.6.176, 2001:6b0:e:2018::1337 <-?????

Connecting to releases.mozilla.org|32.1.6.176|:80... failed: Connection timed out.

Connecting to releases.mozilla.org|2001:6b0:e:2018::1337|:80... failed: Network is unreachable.

With Intrepid: (as it should be)
@wget https://addons.mozilla.org/en-US/firefox/downloads/latest/722/addon-722-latest.xpi?src=addondetail
--2010-05-11 14:11:22-- https://addons.mozilla.org/en-US/firefox/downloads/latest/722/addon-722-latest.xpi?src=addondetail
Resolving addons.mozilla.org... 63.245.213.91
Connecting to addons.mozilla.org|63.245.213.91|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://addons.mozilla.org/en-US/firefox/downloads/file/88048/xpi/noscript-1.9.9.74-fx+sm+fn.xpi?src=addondetail [following]
--2010-05-11 14:11:24-- https://addons.mozilla.org/en-US/firefox/downloads/file/88048/xpi/noscript-1.9.9.74-fx+sm+fn.xpi?src=addondetail
Reusing existing connection to addons.mozilla.org:443.
HTTP request sent, awaiting response... 302 Found
Location: http://releases.mozilla.org/pub/mozilla.org/addons/722/noscript-1.9.9.74-fx+sm+fn.xpi [following]
--2010-05-11 14:11:25-- http://releases.mozilla.org/pub/mozilla.org/addons/722/noscript-1.9.9.74-fx+sm+fn.xpi
Resolving releases.mozilla.org... 131.188.12.212
Connecting to releases.mozilla.org|131.188.12.212|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 479854 (469K) [application/x-xpinstall]
Saving to: `noscript-1.9.9.74-fx+sm+fn.xpi'

100%[===================================================================================>] 479,854 321K/s in 1.5s

2010-05-11 14:11:27 (321 KB/s) - `noscript-1.9.9.74-fx+sm+fn.xpi' saved [479854/479854]

With Lucid:

* Looking up irc.ubuntu.com

* Connecting to chat.freenode.net (32.1.25.240) port 8001...

* Connection failed. Error: Network is unreachable

 Cycling to next server in Ubuntu Servers...

* Disconnected ().

@whois 32.1.25.240

OrgName: AT&T Global Network Services, LLC

NetRange: 32.0.0.0 - 32.255.255.255

...some addresses resolve well:
@ping www.ubuntulinux.org

PING www.ubuntulinux.org (91.189.90.40) 56(84) bytes of data.

64 bytes from www.ubuntulinux.org (91.189.90.40): icmp_seq=1 ttl=50 time=72.8 ms

With Intrepid: (no probs)
* Looking up irc.ubuntu.com
* Connecting to chat.freenode.net (213.92.8.4) port 8001...
* Connected. Now logging in...